In our earlier panel connecting means illustrated in U.S. Pat. No. 4,158,938, fastening screws for gasketed clamping strips on opposites sides of the panels to be connected were screwed into vertically spaced plastic cylindrical double socket members disposed along and partially encased in an edge portion of one of the panels. Alignment problems between the screw holes in the clamping strips and the threaded sockets in the socket members made assembling difficult. This problem of alignment is overcome when one clamping strip is provided on an inner side with a longitudinally extending channel portion for receiving screws for the other clamping strip anywhere along the channel, as in U.S. Pat. No. 3,082,849, but the screws connecting such clamping strips would conduct too much heat into a cold storage room.